Adjustable set-square



J. WESTWOOD.

ADJUSTABLE SET SQUARE. APPLICATION FILED JULY], 1919.

1,342,730. PatentedJune 8,1920.

2 SHEETS-SHEET I.

I 1, "h I L J. WESTWOOD. ADJUSTABLE SET SQUARE.

APPLICATION FILED JULY7| I919.

Patented J une '8, 1920.

2 SHEETS-SHEET 2.

KX'MIM/ZM W Wz/M UNITED STATES WESTWOOD, OF BRIGHOUSE, ENGLAND.

ADJUSTABLE SET-S QUAKE.

Application filed. July 7, 1919.

Z '0 all whom it may concern:

Be it known that I, Janus WEs mvooD, a subject of the King of Great Britaln, residing at Brighouse, in the county of York,

England, have invented certain new and useful Improvements in Adjustable Set- Squares, of which the following is a specification.

The subject of this invention is a setsquare for use in mechanical or other mathematical drawing, the said set-square being of the type in which one side of the device can be moved in such manner as to vary the angle of the said side in relation to the side which is usually laid against the T square; that is to say, in set-squares of this type, the body of the device is made in two portions hinged together, and if one of these portions be held still while the other is moved, the angle between the outer edge of the moving part and the adjacent edge of the fixed part will be altered, a protractor scale being usually marked on a quadrant fixed to one member of the device in order to indicate the extent of the variation.

According to this invention, the two parts are connected together by toggle links, one of which links acts as the pointer, gnomon or indicator of the device.

In the drawings, Figure 1 is a plan view of a set square constructed according to this invention, and showing it closed. Fig. 2 is a similar view, but shows the square when open. Fig. 3 is a view similar to Fig. 1, but shows the set square provided with an additional scale and pointer. Figs. 4 and 5 are plan views showing two modifications. Fig. 6 is a series of various modified forms of hinge connection, shown in plan views.

The reference numeral 1 indicates the main body of the device, to which the hypotenuse or movable arm 2 is hinged at 3.

- The protractor scale 4 is cut or marked on or attached to the body 1. The small link 5 which is pivoted at 6 is intended to work over an arc of 45. The longer link 7 is pivoted at 8, and is connected to the link 5 near the point thereof. By a milled head nut at 9 or other suitable means the pointer link 5 can be tightened in the required position, the link 7 and hypotenuse 2 therefore remaining set.

The set square may be made of transparent celluloid and the hinge and links of brass, or any other suitable materials can be used. The out between the two parts of Specification of Letters Patent.

Patented June 8, 1920.

Serial No. 308,930.

the square is made through from point to point on the 45 degree side, so that it does not cut through any of the sides or spoil them for ordinary drawing use, the 90 degrees angle being always available to suit the direction of the light, that is, it can be used with either side against the T square. An additional pointer or pointers can be placed on the indicator link 5, which may be a flat plate, in order to show gradients or other special measurements, as represented in Fig. 3, where the rear end of the link 5 is provided with an extension pointer 10 working over an additional scale 11, and 1n Fig. 4, where three such additional pointers, 10, 12 and 13 are provided, indicating on scales 11, 14 and 15 respectively.

Fig. 5 shows a modification wherein the pointer link takes the form of a transparent plate of celluloid 54: carrying the scale, which turns around its pivot 6 until the desired indication is shown by a selected mark on the scale coinciding with a black line which crosses a white or colored spot or background 16 on the main portion 1 of the 7 device.

Fig. 6 illustrates examples of other designs of hinges which may be used in place of the hinge plate indicated at 3 in Figs. 1, 2 and 3.

Claims.

1. In a set square, a triangular main portion, a side portion pivoted to the main portion at one of its angles, a relatively short member pivoted to the main portion, means for locking the short member to the main portion, and a link member of greater length than the said short member and pivoted to it and to the said side portion, the said short member and the main portion of the square being provided with scale and index members one of which is stationary with respect to the other and operating conjointly to indicate the angular position of the side portion with respect to the main portion.

2. In a set square, a triangular main portion, a side portion pivoted to the main portion at one of its angles, a relatively short link member pivoted to the main portion and provided with a pointer at one end, said main portion having a stationary scale arranged to indicate the position of the said pointer, means for locking the link member to the main portion, and a relatively long link pivoted to the link member and to the said side portion.

3. In a set square, a triangular main portion, an adjustable side portion pivoted to one of the angles of the main portion, a relatively short link member pivoted to the main portion and provided with two pointers arranged one on each side of its pivot, said main portion having two stationary scales to indicate the positions of the respective pointers, means for looking the 10 said link member to the said main portion,

and a relatively long link pivoted to the said link member and to the said side portion of the square.

In testilnony whereof I affix my signature in the presence of two witnesses.

JAMES WESTWVOQD.

Witnesses:

ERNEST PRIESTLEY NEWTON, JOHN SYLvANUs BURROW. 

